Intel TDX module: Insufficient control-flow management in the TDX module lets a privileged host user deny service

Impact

Insufficient control-flow management in the TDX module lets a privileged host user deny service - i.e. the host can wedge confidential VMs. Availability rather than confidentiality, but on a confidential-compute product the host being able to kill TDs at will is still a boundary the design claims to hold.

Who can reach it

Privileged host user.

What to do

Update the Intel TDX module. The TDX module is loaded by the SEAM loader at boot, so the practical rollout is: stage the new module, drain every trust domain off the node, and reboot. It is not a live-patchable component and running TDs cannot be migrated through it. After the update, every TD must re-attest because the TDX module SVN is part of the attestation report - so anything that pinned the old measurement will fail until you update your attestation policy too. No OEM BIOS release needed for the module itself, which makes this materially faster than a platform firmware update.

References